American Locomotive Practice

38 COWAN ON AMERICAN LOCOMOTIVE PRACTICE. [Minutes of

31 March, 1903. JOHN CLARKE HAWKSHAW, M.A., President, in the Chair. The PRESIDENTannounced that acommunication had been received by the Council from the American Society of Engineers, expressing a hope that on the occasion of the Exhibition at St. Louis, in 1904, the members of theInstitution would visit America. If they did so, the American Society mould be glad to receive them and would make their visit as pleasant as possible. Formal notice of the invitation, as well as some proposals of the Council with regard to its acceptance, would be forwarded to the members in duecourse.

(Paper No. 3398.)

I‘ American Locomotive Practice.” By PERCYJOHX COWAN, Assoc. M. Inst. C.E. ONEof the most prosperous industries in America at the present timeis that of locomotive-building ; and theAuthor proposes to give in this Paper some ncjtes on current American practice in such work. Before passing, however, tothe consideration of details of construction and to the description of various modern designs of locomotives, it may be interesting to consider how the locomotive industry in America, which has been built up in comparatively recentyears, is supported, when compared with thesame business at home. In England,nearly all the leading railway companies own works, in which they not only repair their locomotive stock, but are able, as a rule, to meet therequirements of theline as regardsnew engines. Smaller English companies, and even the larger lines, are forced from time to time to make contracts for new engines, if they have not the means, or the works have not the capacity required, to turn them out within a reasonable time. Thusthe London andNorth Western Railway and the Great Western Railway build all the engines they require; while the

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] COWAN ON AMERICAN LOCOMOTIVE DISTRICT. 39 Great Northern Railway builds all its passenger locomotives and many goods engines, buthas often had to make contracts with the leading English locomotive builders for further goods engines. The Midland Railway is inthe same position;and, as is generallyknown, both these two lines and the Great Central Railway had recourse to American works in 1899, when a demandfor B large increase of motive power suddenly arose. British locomotive builders, however, are not dependent for their trade so much on the home lines-or at least not on the larger of them-as theyare on the colonial railways;and at least one-half of the work done in British locomotive shops is to go beyond the seas. A steady business is being done withSouth Africa, India, Australia, etc. ; and if this tradeis slack, there is but little inducement for the builders at home to enlarge or improve their works. In America, or more particularlyin theUnited States, theposition is theopposite. With one or two exceptions, the lines in the States do not own works at which they build locomotives : so that all demands for increased power are met by the large contract shops in the eastern States. Again, America has no colonial trade in locomotives ; and the few engines built in that countryfor export are often for foreign railways that are in such a dilemma as con- fronted some English lines in 1899. On the other hand, it must be admitted that American builders have for several years been making strong efforts to secure some of the foreign markets, and in a few quarters have met withsome success-for instance, in Russia and in China. It is evident, therefore, that the contract shops in theStates have an enormous home or domestic trade; in fact, they have thelocomotive-building of the country in theirhands. The Pennsylvania Railroad is one of the few lines that build their own locomotives; and in busy times, such as the present, it can cope with only the passenger requirements of the line, and places largecontracts for goods engines, and sometimes even for a few passenger engines. Other lines, such as the New York Centraland Hudson River Railroad, occasionally design their own locomotives, and build perhaps one of a class: if it proves satisfactoryafter aprolonged trial, a contractis madefor the remainingnumber required. As a rule, however, therailway names the kind of engine desired, and gives particulars of any featuresto be embodied therein;furnishes drawings, etc., of any special fittings; states dimensions or gauges tobe adhered to;and gives thelimits of weight, load-gauge, etc. The contractors then prepare their own design, subject, of course, to the

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 40 COWAN ON AMERICAN LOCOMOTIVEPRACTICE. [Minutes of approval of the superintendent of motive power for the purchasing line,and the engines are built. Oftena few notes, regarding traffic requirementsand the quality of certainmaterials to be used, are the only restrictionsplaced upon the contractors’ work. Such methods tend obviously to reduce the first cost of an engine; for thecontractors can practicallydesign the machineto suit themselves. This practice is carried tosuch a lengththat a foreign railway buying an engine in the States must be content with an American engine, if delivery is required within, say, a twelvemonth. For instance, most American firms absolutely refuse tobuild an engine with slab or plate frames, though some will now buildslab-frame tenders. In England,the purchasing railway, if it be large, will supply all drawings down to the minutest detail ; so that the locomotives built by contract may be the same as those built in the company’s own works, and may have parts interchangeablewith them. So far as theAuthor knows theonly American line which regularlyfollows this practice is the Pennsylvania Railroad. As a result, other lines aresupplied, at each contract, with engines which differ inalmost every detail fromthose last ordered. From the mere fact thatthe builders may suit themselves, their engines are cheaper in first cost than English engines, but in repairs they must become much more expensive. In small orders,such as have at times been executed by the Baldwin Locomotive Works, the accumulation of designs enables parts to be pieced together quickly, if a design is needed without delay; but it must be allowed thatgenerally the designing is carefully done. Thedrawings are not so elaborate as those in use in English works. Shop-drawingsor blue-prints are seldom accurate, or even drawn to scale. All work is done from card-prints, varyingin size between about 12 inchesby 15 inchesand G inches by 8 inches ; and one card often serves for several orders, because the variabledimensions are lettered, and thesizes are filled in on lists alongside, according to the contracts. In regardto standards and to interchangeability of parts, a belief is current that standards are more in use in America than in England; but in the main it isnot so in the locomotive world. So far as the use of templates is concerned, it is perhaps true : all work for one order is marked out withtemplates whenever possible. But this is now done almost without exception in British works. A far more important point, to a large railway owning one or two thousand locomotives, is not only to have the engines of a small contract alike, but to have them similar to others already on the

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Pro~ings.1 COWAN ON AMERICAN LOCOXOTIVEPRACTIOE. 41 line: in other words, to reduce the whole locomotive stock to as few classes as possible. At home this practice is carried to a con- siderablelength; whereas in Am.erica thematter seems to be almost ignored, save in a few instances. For example, one line in England has six or seven standard classes, many of them with similar parts. Another has seven standard types, three of them with similar boilers. Details such as boiler-mountings, and much of the valve-gearing,can be made interchangeable ; wheel-bases are standardized, so that side rods of express engines can be alike ; and SO on throughout. In America this side of the matter seems to be neglected There is a steady demandfor heavier locomotives. Alllines havenow much heavier engines than they had even 2 or 3 years ago ; and ineach order that is given the engines areheavier than in the last, withsufficient difference in details to destroy all idea of standardization. During such a busy time as the last 2 or 3 years, anotherquestion has to be considered by the superin- tendents of motive power. For some years past all the leading builders have had their hands full (of work ; and if an order for, say, twenty or thirtylocomotives has been given out, the contract has been divided between two or more firms, in order to obtain the completion of the engines within a reasonable time. In such a case, unless full detail drawings were supplied by the railway to the contractors, further differences would appear in engines which wouldotherwise have been of one class. The wheel-diameters may be thesame, the heating-surfaces, and weights approximately the same, and also those fittings which are supplied by otherfirms ; but the engines of the two builders will be different. Wherever drawings, etc., are supplied to the contractors, more time is required, and the first cost is considerably higher ; moreover, inspec- tors on behalf of the railways often have trouble in getting the contractors to adhere strictly to the drawings in mattersof detail. A great deal hasbeen said of late years about thefinish of Ameri- can work. “ Finish ” at home is often carried to a great length ; and in this matter it mustbe allowed that Americans take a sensi- ble stand. An enginecan work as well with therods buffed or black painted as if they are draw-filed and finished with emery-cloth. Again, except as a convenience in discovering flaws, etc., it matters little to the working of the engine whether the reversing-shaft is finished all over, or is left black; or whether the axles are turned up all over. But more than this “surface cleaning ” is included in the word “finish,” which does not mean merely polish, but includes good fitting: so thatwhen parts are assembled in the

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 42 COWAN ON AMERICAN LOCOMOTIVE PRACTICE. [Minutes of erecting-shop they correspond, and fit intotheir proper places. In thismatter Americanshops do not hold thehigh position often ceded to them ; and in manyof them, for lack of time, work is done that would not be tolerated in England. The subdivision of work, as carried out in the large contract shops abroad, does not make good fitters of the men. In erecting-shops, for instance, one gang will be employed to set the frames, another gang to set the boiler in them,and other gangs will put up the motion : until a number of different gangs have each done a little at each engine. Thus men become accustomed to do just one kind of work, andcan do thatfairly smartly, whence theadvantage to the firm: but, should some hitch arise, and a little more hand-work than usual be necessary, the average workman makes but a poor show. So far asmachined work is concerned, the finish is good ; but hand-work is considered to be finished as soon as it is sufficiently completed to serve its purpose. For instance, in boiler-work the edges of plates, so longas caulking is not interfered with, are left as they come from the punching-machine. Anglesand tees are sheared intolengths, and the rough edges are not even touched with the grindstone. Firebox-stays are run in by machine, piece-work; andin one instance of copper stays used with steel fire-boxes, fully 30 per cent. of the stays as originally put incould be turned round with the fingers alone. On being taken out, they were found in many cases tohave the thread on the inside end completely cut off, owing to their havingbeen forced into the second sheet.’ Castings are frequently not sound, simply because due care has not been exercised in keeping the moulds free from dirt. Such castings as large cylinders, and often smaller cylinders, are frequently porous, or have dirt and grit imbedded in the metal; and such cylinders are often accepted, evenpatched or plugged, by American lines, when work of like description would at home be rejected by the contractors themselves, even without reference to the inspector. Castings are used wherever possible, and are left rough where possible. Instead of highly machined and finished wrought-iron eccentrio-straps, general practice is satisfied with a heavy cast-iron pattern lined with whitemetal.

In fairness, however, it should be mentioned that in this instance the plates were of steel, while the stay8 were of copper-a much softer material than the stay-bolt iron generally used for the purpose in American practice. Hadthe llarder material been used the work would probably have been somewhat better in quality: and the example is cited as showing the rough manner in which work is apt to be done under methods in vogue.-P. J. C.

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] COWAN ON ADIERICAN LOCOMOTIVE PBACTICE. 43 Smiths’ work is usually rough, especially so if the article is to bemachined afterwards ; for smiths’ work is expensive when compared with machine work, and is therefore somewhat hurried over. In frames the work is sometimes so rough that, when eight are placed in a pile on the shaper, a,fter being marked off, over an inch of metal has perhaps to be cut away on a radius on some forgings,before others in the pile are touched. Bad welds, and cracks from workingthe metal a,t too low a temperature,are not infrequent ; and often the work has to go back to the forge or smithy. In such work as fitting boiler-mountings and making steam- tight joints, Americanpractice is good, and will be dealt with later.Working parts are carefully made. Journalsare rolled with a tool in the lathe after being finished; rods are accurately fitted, and when put on the line it, is not often that American- built engines give trouble from hot bearings, etc. In justice it must be said that American work is accurate in such parts as side rods, etc. ; and it is seldom necessary to take down such rods for alteration, when. once they have been tried up. Generally speaking, the methods used are good in themselves; methods of setting up work on machines are satisfactory; but too little care and attention is given .to the work in hand, and the resulting machine is but poorly finished and put together. The materials used in American engines are generally of good quality, and it is seldom that material fails to stand the specified tests. As a rule, the tests aresevere, and the analysis strict.

DETAILSOF AYERIC~NLOCOMOTIVES. CyZindela.-The cylinders are a distinctive feature of American design, but one whichhas recently been adaptedto English practice. Thecylinder-castings bolt together down thecentre line of the engine, and that portion of the castings between the frames supports the boiler, or rather the smoke-box. Each casting is knownas a half-saddle. In ordinary non-compound engines it is universalpractice to make the cylinders interchangeable, thereby requiring only one pattern for the foundry, and simpli- fying much of thesubsequent work on thecastings in the machine-shops. Whilein England practice has tended towards casting the two cylinders together,and forming the back cylinder- cover solid with the casting, in American work the cylinders are always cast separately, and with a plain barrel; while covers of

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 44 COWANAMERICANON LOCOMOTIVE PBACTICE. [Minutes Of full diameter are fitted to both back and front ends. The steam- chest for a “ D ” or balanced slide-valve is a separate casting ; but,when piston-valves are used, it is incorporated in the cylinder-casting. Good close-grained ironis used, but,as mentioned, theworkmanship and quality of thecastings are not always good ; and the Author has known castings, which at home would be judged poor, to be put into new engines andaccepted. A deviation from the usual practice-rather a return to old practice than a novelty in design-is noticeable on the Pennsylvania Rail- road, Fig. 1 (e), Plate 3, and in the recent heavy “ decapods” on the Atchison, Topeka and Santa Fe Railway. Here the cylinders and saddle are made in three castings, instead of the more usual two. The main casting goes between the frames, and forms the support for the boiler, and of the centre casting of the four-wheel truck, should the engine be fitted with one. Thetwo cylinders bolt on outside the frames, whichhere take the form of thick slabs. With the large castings needed at the presenttime, this arrangement has some advantages worthy of notice, namely :- (1) foundry-work is simplified ; (2) the cylinders may be of hard iron chosen to withstand wear, while the centre casting may be made of softer and tougher material better suited to withstand shocks; (3) in case of accident a cylindermay be renewed withoutdisturbing the frame or boiler. On thePennsylvania Railroad, Fig. 1 (e), the exhaust passes through the slab and up thecentre casting; and live steam is conducted throughan elbow casting which connects the steam-chest passages with the saddle. Atthe present time piston-valves arelargely used, bothin passenger and in goods service. The Brooks and the Schenectady Works of the American Locomotive Company build many engines with piston-valves, as does also theBaldwin Works,where all Vauclain compounds are fitted with them. The other valves used are invariably balanced valves of the American, t,he Richardson, or the Allan-Richardson designs. Noticeable designsin cylinders are the compounds of the Southern Pacific, Fig. 1 (A), andother lines, builtby the Schenectady Works, having one low-pressure cylinder 35 inches in diameter, with aslide-valve, and one high-pressurecylinder 23 inches in diameter, with a piston-valve. Four-cylinder engines are in very general use. The best known of these is the ordinary form of Vauclain compound, with two cylinders placed on each side of the engine, one above the other, Figs. 1 (f and g). Some years ago, a tandem compound was

introduced by the Brooks Works ; and tandems have been experi- mented with for some time on the A.tchison, Topeka and Sante Fe Railway. The past year has seen great developments in tandems, andlarge orders for this class off enginehave recently been executed. Other four-cylinder enginesinclude a type known as the four-cylinder Vauclain balanced compound, in which two cylindersare placed insidethe frames andtwo outside. Such cylinder-arrangement is not new to:English practice. Figs. 1 (a and b) show two typical single cylinders: (a) is that of the standard 20 X 28-inch cylinlder of the New York Central and Hudson River Railroad, used on the ten-whoeled passenger engine shown in Fig.17 (f),Plate 6 ; (b) is that of the Pittsburg, Bessemer andLake Erie Railroad ‘‘ Consolidation ” engine in Pig. 18 (a). The spread of thecylinder-centres varies between about 7 feet 2 inches and 7 feet 73 inches; while the valves are about 2 inches to 4.$ inches within this on each side. Thus, with cylinder-centres 7 feet 2 inches apart, the valve-centres may be as much as G feet 8 inchesor more :&part. Engineswith piston- valves gain somewhat in this respect, because their valve-centres may be 3 feet 9 inches or less apart, whereby the length of the rocker-arm is reduced with its attendant troubles, and the valve is brought nearer the line of motion of the eccentrics and links, besides being placed almost directly over the frame-centre, as shown in Fig. 1 (d), which is the cylinder for the large twelve- wheeled Brooks engine on the Illinois Central Railroad. In good practice a cored space is always provided between the steam and exhaustpassages in the casting (Figs.1, a and b), so that the lower temperature of the exhaust, mayagect as little aspossible the higher temperature of the live steam. No live steam is any- where in touch with scraped or faced permanent joints, as it is in English practice, where the cylinders are bolted together, so that the steam-chest is formed between them. The joints between the cylinderand steam-chest, and between the steam-chest andits cover, are made with coppergaskets. The cover-joints of the cylinder are ground by standing the castingson end under a large drilling-machine, before the studs are put in ; the spindle of the machine is fastened to the cover, which is rotated by the machine being set in motion. Theground face is narrow, beingwholly inside thecircle of studs ; and thecover and cylinder-casting outside the ground face are turned well clear, sometimes by as much as & inch. Steam-chest castingsand covers and cylinder-covers are of cast iron or cast steel, Figs. 2 (Uand b) show the steam-chest arrangement, and (c) is a design of cast-iron cylinder-corer of large

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 46 COWAN ON AMERICANLOCOMOTIVE PRACTICE. [Minutes Of diameter.Cylinders are often bushed withliners of veryhard metal. Not merely are liners inserted in old cylinders bored out, but cylinders of new engines are fitted with them; for instance, the Chicago and North Western engine, Fig. 17 (b), Plate 6, of which the cylinders areshown in Fig. 1 (c). Pistons.-Exsmples of pistons are given inFigs. 3, Plate 4, from which it will be seen that they are either hollow or cast solid. Figs. 3 (U) show the most usual form of cast-iron hollow piston, the core-holes being afterwards plugged as shown. Pig. 3 (a) is thesimplest possible form, a plaindisk piston of cast steel for35-incha low-pressure cylinder of a compound on the Southern Pacific Railroad. Fig. 3 (c) isthe piston for a 24 X 33-inch cylinder on the Pittsburg, Bessemer and Lake Erie Railroad engine shown in Fig. 18 (d), Plate 6. It is composed of the piston proper, a bull or junk ring, and a retaining ring. The walls are of cast steel -g inch thick. A similar piston is used on theIllinois Central Railroad“Consolidation ” engine, Fig. 18 (c), in which case the walls are -& inch thick only, for a cylinder 23 inches by 30 inches. Fig. 3 (d) shows another common piston, composed of acast-iron spider, a steel follower, and a cast-iron bullring; it is exceedingly popular and very satisfactory in service. Dished or conical pistons are occasionally used, in order to meet some special feature in the design of the cylinders ; but they are notgeneral. Thepacking for smallpistons consists of theordinary snap rings, which are sometimes used a1so for larger sizes ; but for the latter most lines use other kinds, such, for instance, as the Dunbar packing illustrated inFigs. 3 (c and d). Piston-rods.-The piston-rods are of wrought iron. Theyare sometimes hollow, as in Fig. 4 (a), which shows a cross-head in use for Vauclain compounds on the Baltimore and Ohio Railroad. Usually 3$ to 4$ inches in diameter, they fit into the cross-head with a plain taper end, or a taper fit and collar. Into the piston they are fitted with an end tapered fr or 2 inch in 12 inches, and fixed by a collar and nut in frontof the piston as usual. Extension or tail rods are largely used on some lines for all cylinders over 19 inches in diameter. They are encased in tube casings or castings. The packing for the extension rods is as a rule simpler than that used in the glands proper, and sometimes consists of only plain split bushes and neck rings. Cross-l~eads.-Many forms of cross-heads and slide-bars are inuse. The most usual comprise the top- and bottom-bar form, Figs. 4 (a and b), the two-top-bar or Laird cross-head (e), and the four-bar

kind (c and d). The single-bar is notcommon. Some railways have patterns peculiar to themselves, such as that, on the Pennsylvania Railroad, where a bar of section. isused with the slipper of the cross-head working inside it. The Vauclain compound necessitates a special cross-head to take the two piston-rods, one above and one below the bars, as shownin Fig. 4 (d). Cross-heads are of cast steel. Slippers areof cast or wrought iron or cast steel, lined with white metal; or of brass. The wearing-surfaces are ample, being, as a rule, in excess of what are considered necessary in England. The top bearingsurfaceof the two-bar cross-head is frequentlyof larger area than the bottom in locomotives which run always in forward gear. Vauclain compound cross-heads are often recessed for lightness, so thatthe slippers are of channelsection3 (Fig. 4 d). Cross-heads are very large, frequently much as as 29 inches longon the slipper. The cross-head (a) in Figs. 4 has a wearing-surface of 132 square inches for the top bar, while (b) has a surface of 160 square inches for the top bar and110 square inches for the bottom. The four-bar arrangement provides about the same, namely, (c) 126 square inches; while the Lairdcross-head (e) gives 168 square inches for the top bar, but considerably less for the lower. The gudgeon-pin bearing-surface is about 4 inches long, and at the centre the pin is 34 to 5 inches in diameter. Value-motion.-The valves are actuated, almost without exception, by theordinary Stephensonlink-motion. Therods are short, andthe motion jerky; besides whichthe movement is transmitted from the block to thevalve-spindle through a rocking shaft. The arrangementof the wheels oftennecessitates bending the valve- rod between the link and the rocking-shaft or so arm, as to avoid an axle, as shown in Figs. 5, Plate 3. Fig. 5 (U) is a design in use on thePennsylvania Railroad G4 clam of engines;while (b) is a design by the Baldwin Lozomotive Works. As a rule the links are built up with bolts set rndially : the link with Etraight bolts shown in Fig. 5 (b) must be considered exceptional. A few lines use solid links, as is evident from Fig. 5 (a). In passenger engines and some others, provision is made for the circular movement of the end of the rocker arm ; but such provision is by no means universal, and inmost engines thelong valve-spindle rods are connected directly to the rockerarm. This does not appear to be good practice ; for, although the arc moved through is not large, thevertical movement is considerable wheneven it &inch valve-travel has to be produced by a rocker arm 10 to 11 inches long. The Pennsylvania Railroad and some others provide for thisvertical movement by prolongingthe spindle into L

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 48 COWAN ON AMERICANLOCOXOTIVE PRACTICE. [&Iiuntcs of guide, the motion from the arm being transmitted toit by a sliding block and guide. Eccentric rods are provided withadjustment, used when the valves are being set : after which the permanent holes are drilled inthe rods. Eccentricstraps in ordinary practice are of cast iron, rough on the outside. Fig. G (a), Plate 3, showsa typical casting,which is rather heavy and clumsy. Fig. 6 (b) shows a casting of channel section, used on the New York, New’Haven and Hartford Railroad ; while Fig. 6 (c) illustrates a web andflange section introduced by theBrooks Locomotive Works in engineson the Union Pacific Railroad. These last are made in malleable cast iron, and are at thesame time bothlighter andstiffer than themoreordi- nary form. Two patterns servefor all foursets, Le., one pattern for each half; the oil-cups and holes, etc., which come at the bottom, are plugged. As a rule, the eccentrics are cast singly. Sometimes they are cored out and lightened as in Fig. G (a), a design also by the Brooks Works. They aremarked off when the wheels are under the engine, the reversing-quadrantalso being marked off in position. No balance-weights areused; their place is takenby a light plate-spring or by a coil-spring, Figs. 5 (U and b). The reversing- or reach-rod is frequently made of heavy wrought-iron pipe, as in most of the Brooks engines. Frames.-Though theoriginal bar frame is used inthe vast majority of American locomotives, recent years have seen many lnodifications therein. A simple bar frame is made up of the top rail or bar, jaws or pedestals, and bottom tie-bars. It is connected to the cylinders by front rails or splice-bars, of which there may be one, two, or three,Figs. 7, (a, .f, and h), Plate 3. The nlain frame is 4 to 5 inches thick, and the top bar is 4 to G inches deep. One step removed from this is the Brooks frame, shown in Figs. 7, (cl and g), with the front rail worked down into a deeper and thinner slab than the rest of the frame, which is of squarer section. The cylinder arrangement of the Pennsylvania Railroad and of other lines necessitates deep slabs for the front portion of the frame; this modification, Fig. 7 (e), is almost a compromise between the English slab frame and theAmerican bar frame. Other special frames are shown in Figs. 7, where (c) represents that frame of the Chicago and North Western Railway‘;Atlantic” engine,buiit by the Schenectady Locomotive Works, having atthe trailing end outsideframes and outsidebearings. The trailing-end arrangement is almost identical with that on the 930 class of the Great Northern Railway of England,and was not brought out until fully 2 years after the Great Northern engines

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] COWAN ON AMERICANLOCOMOTIVE PRACFIUE. 49 had been built. Fig. 7 (cl) illustrates the frame used in engines fitted with the Player radial truck : radial castings of steel, of style similar to those in Mr. F. W. Webb’s London and North Western Railway arrangement, are used between the frames. A still more recent introduction for rnain-line work is a plan, by no means unknown in England, of cutting short the mainframes just in front of the fire-box, fixing to them a heavy steel cross- piece,and continuing withoutside bar-framesfor the trailingwheels, which are provided with outside axle-boxes and bearings. This form has been used for some years on the Chicago, Burlington and

Quincy Railroad, and has been adopted on a heavy ‘L Atlantic ’’ class of enginesrecently built for thatline by the Baldwin Works. The pedestals are protected by cast-iron or steel gibs or shoes, one of which is provided with a wedge. The taper of the front pedestal is about 1 in 12, while the back pedestal is almost invariably vertioal. Theplan of taperingboth pedestals has practically been abandoned. The bolts used for fixing the front rails to the main frame are tapered bolts l+ inch to 1%inch in diameter. Keys are often used at the splices, and in some engines the frame-bars interlock. Yoke.-The yoke, known inEnglish practice asthe motion- plate, is of heavy wrought-iron plate about 18 inch thick, which stretches rightaoross the engine, thus adding to thestiffness of the frames. A cast-steel yoke-piece is sometimes used in connection with a slab across the frames, as ;shown in Fig. 8 (d), Plate 3. In most engines the yoke is fixed to the frames by brackets ; but the Brooks Works forges a standing support upon the frame, as for instance on the Burlington, Cedar Rapids and Northern Railroad, and on the Illinois Central Railroad, Figs. 7 (cl and g). In some recent engines (e.g. the “Prairie ” class by the Brooks Works) it has been found a matter of such great difficulty to secure the yoke to the frames, that it has been fixed to the boiler-shell instead. However necessary this may be rendered by the wheel-arrange- merit adopted, it can never be considered a desirable plan, and 6eemS to be, if anything, a backward. step. ,!j’lide-Bara.-The slide-bars and oross-head must of necessity correspond. The top-and-bottom-barplan seems more usualfor passenger work, and the four-bar for goods service. There are SO many exceptions to this, however, that no rule can be laid down. The Chicago andNorth Western Railway and the New York Central and Hudson River Railroad use the four-bar in passenger engines.Again, one firm of builders recommends the top-and- [THE INST. C.E. VOL. CLIV.] E

bottom-bar for all work. The Laird arrangement, Fig. 4 (e) and Fig. 8 (U), is popular for goods service. Thebars are usually of wroughtiron; but within the last 2 or 3 years cast steel has been used, and seems to have answered the purpose. When cast steel is used in the four-bar or the top- and-bottom-bar arrangement, a considerable saving in weight may be possible;for thebars may be made of L oror T section Fig. 8 (d) illustrates cast-steel guides for a Vauclain compound on the Baltimore andOhio Railroad. The bars are fittedto lugs on the back cylinder-cover, and on to the yoke at or near their back end. Wheel-arrangementand other considerationsoften render it impossible to place the yoke atthe end of thebars; and, all things considered, it would seem that some intermediate position is preferable. On the road it is thegeneral opinion thatbars supported by theyoke at some distance from their end give better running, and are less liable to become heated. As a rule bars vary in section, being heaviest in the centre, or at the yoke if this is not placed at the end. Theusual four-bar typeand the Laird cross-head prevent the yoke from being placed elsewhere than at the end of the bars. Wheel-Centres.-The wheels are of cast iron or steel. The few forged wheels which are made are mostly for trucks and tenders. Driving-wheels of largerdiameter than 4 feetare now almost invariably of caststeel ; many of thesmaller sizes are of the same material,though for these cast ironis more usual. Passenger engines and fastgoods engines are alwaysprovided with cast-steel driving-wheels, and preferablyforged truck-wheels ; some lines, however, still use chilled cast-iron wheels for thetruck. The counterbalance is cast with the wheel; but, though solid in coupled wheels, it is usually cored out in the main drivers and afterwards filled with lead. The section of the spokes varies. The Baldwin and Schenectady Works recommend an oval section, whilethe Brooks Works and thePennsylvania Railroadkeep to a section whichis nearly rectangular, Figs. 9, (U and b). In good practice themetal in the hub, and also that in the rim, is massed immediately over the tread, i.e., towards the inner side. Many wheels, cast-iron as well as steel,show a web between the spokes, extending out some distance from the hub, which is for the purpose of diminishing the internal strains setup in cooling. To relieve these strains, also, it is usual to cut the rim through in three orfour pIaces, two of the gaps being placed one on either side of the spokes running into the crank-boss. In the subsequent work in the shops, these gaps or cuts aremachined

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. PWedingE.] OOWAN ON AMEBIUAN LOCOATOTIVE PRACTICE. 51 up, iron wedges are tightly driven in, and the rim is turned after they have been inserted. When steel was first introduced as a material for wheel-centres, the possible saving in weight was oonsidered one of its greatest advantages. This matter is not pushed so far now as it was then. Manydesigns since abandoned show hollow hubs and hollow crank-bosses ; but the difficulties of oasting and the extra expense of cored castings have caused simpler designsto be more generally used. A leading firm of American manufacturers give the following as the relative weightsof cast-iron and cast-steel wheels suited to identical service :- Ratio. Cast Iron to Cast Steel. Passenger service, over 4 feet 8 inches in diameter. . 1 : 0.6 ,, ,, under ,, ,, ,, . . 1 : 0.7 Goods ,, ...... 1 : 0.8 The rims of the castingsare hollowed out as arule. Truck- wheels are usually fitted with their tires before being pressed on tothe axles. For wheels of largediameter retaining-rings are used for the tire, while smaller sizes are provided with a lip only. Set-screws, common in English practice, are scarcely ever used. Steel for wheels is of the quality used in general locomotive castings.Different linescall for slightly differenttests. The Chicago and North Western Railway requires a minimum tensile strength of 26-8 tons per square inch, with an elongation of not less than 15 per cent. in 8 inches. The Lake Shore and Michigan Southern Railway requires an ultim,ate tensile strengthof not less than 27 7 tons per square inch, with an elongation in 8 inches of not less than 18 per cent., and 2<5per cent. contraction of area. The Philadelphia and Reading Railway allows a range of tensile strength between the limits of 26.8 ,tonsand 33.5 tons per square inch,with apercentage elongation in 2 inches of 1,800,000 + tensile strength in pounds per square inch, or between 24 and 30 por cent. Some lines also insist on analyticaltests as well, e.g., the Chicago, Milwaukee and St,. Paul Railway :-silicon not more than 0.40 per cent. nor less than 0.20 per cent. ; phosphorus not more than 0 *05 per cent. Drlop-tests forwheel-centres are rarely asked for. Tires.-Drop-tests for tires are not usually called for, but they are requiredmore frequently now than they werea few years ago. Chemical and mechanical tests are made as usual. For tire-material one firm requires' a tensile strength of between

1 The English ton of 2.240 lbs. is aeed throughout this Paper. E2

49 * 1 tonsand 55.8 tons per square inch, with an elongation of 10 to15 per cent. in 2 inches;while another demands 44-6 tons to 48.2 tonsper square inch, with aminimum elongation of 16 percent. in 8 inches. The limits forchemical analysis may be taken as :- Carbon between . . . 0.60 per cant. and 0.70 per cent. Siliconnot exceeding ...... 0.25 ,, Phosphorus not exceeding ...... 0.05 ,, Manganese not exceeding ...... 0.50 ,, Sulphur between . . . 0.02percent.and 0.04 ,, Some lines vary the tests according to the service for which the tires are intended. Tires forpassenger service may be required tohave an ultimate tensile strength of 46.9 tonsper square inch, with an elongation of ,l6 percent. in 4 inches. Tires for goods service musthave a tensile strength of 51.3 tonsper square inch, and an elongation of 14 per cent. in 4 inches; and tires for yard or switching service 55.8tons per square inch, and 12 per cent. elongation in 4 inches. Flangeless tires are not used to the same extent as formerly; but this point is not evident from Plate 6, where, with one or two exceptions, all tires areshown with flanges, whereas a few of them are really blank. Axles.-Drop-tests are required for axles ; a standard test calls for a tup of 1,640 lbs., supports 3 feet apart, andfive to seven blows from a height dependingon the diameter of the axle, the axle being turned over after the first, third and fifth blows ; the maximum deflectionallowed is 8 inches.Tensile testsrequire an ultimate strength of 35.7 tons per square inch, with an elongation of 18 to 16 per cent. on 8 inches, and a contraction of area of 35 per cent. Driving-axles are machined all over, totake the eccentrics ; other axles areleft roughbetween the journals.They are all plain, without collars. The journal is of larger diameter than the centre of the axle, and in good practice the wheel-fits are larger again than the journals. Wheels areforced on their axles with the usualpressure of 10 tons per inch of diameter; but the pressure is less for bogie- or truck- wheels. Steel centres are applied at higher pressures than cast- iron. Journals of driving-wheels often attain to 10 or 11 inches in diameter by 12 inches in length. Axle-boxes.-The axle-boxes are of cast iron or cast steel with brassbearings pressed in. As the box is of hardmaterial, considerable wear has been found to take place between it and the hub of the wheel-centre. In order to reduce this wear, either the inner side of the hub is faced with a hub liner, as shown in Fig.

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] UOWAN ON AMEBIOAN LOCOMOTIVE PRACTICE. 53 9 (a), Plate 3, or the outside of the box is faced with a similar protection, as in Fig. 10. The facing consists of a brass plate inch or p inch thick, which foraxle-boxes is sometimes fixed withset screws letinto the brass, but forwheel-centres is forced inby hydraulic pressure. The Pennsylvania Railroad recesses the wheel-centre, and then casts the brass liner in the wheel itself, machining the exposed side afterwards. The crown of the axle-box is cut away inside to a radius struck from a point a good deal higher than the centre of the journal ;and a brass bearing is forced in at a pressure of about 20 tons per square inch for a cast-iron box, a fitting allow- ance of & inch being given to thebrass. Tmcks.-Of late severaldevelopments have appeared in contriv- ances intended to shorten long rigi.d wheel-bases : namely, four- wheel, two-wheel, and radial trucks. The first are generally used in passenger service, though in recent passenger engines one of the two-wheelforms has been reverted to. A four-wheel truck consists of a rectangular frame of bar-iron, to which are bolted eight pedestals. The pedestals are connected by stay-rods across the frame, and by longitudinal stayson each side, Fig. 11 (c), Plate 4. Castings are used for the centre, which is hung on inclined links or on " three-point " hangers. The IPenxisylvania Railroad uses a truck similar to English patterns, namely, one composed of slab frames connected by heavy transverse centre castings, Fig. 11 (a). This figure shows the " three-point " hanger, which is said to work much more easilythan the usual swing-link. The advantage lies in thefact that as the truckmoves over, the point of suspension moves so that the load is suspended from the point farthest from the vertical, to whichever side the truck swings. With the swing- link, whenon a curve, the load on one side is acting ina line nearly approaching the vertical, while the other linkinclined is more and more as the truck swings fartherover. The more the truck moves to one side, the more tilted becomes the centre casting, the highest pointbeing on the side to which the centre is forced. In thethree-point hanger this tilting is abolished, andthe links being parallel, the weight is equally divided between them ; while the centre being thrownmore to one side ensuresa ready tendency to return to themid position. Four-wheel trucks are sometimes braked, e.g., Fig. 11 (a), but braking seems not to be considered so necessary-as formerly, nor to be attended with danger. The arrangements at the leading end of the engine have received much attention lately, inorder to ensure safety on entering

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 54 COWAN ON AMERICAN LOCOMOTIVE PRACTICE. [Minutes of curves, and also to reduce the wear on the flanges of the leading driving-wheels. Theusual four-wheel truckis centred midway between its axles, but the Pennsylvania Railroad is now using truckswith the centre set back towardsthe trailing axle, 8 feature in use for many years on the Great Northern Railway of England,and on other home lines. ThePennsylvania Railroad sets back the centre as much as 94 inches behind the centre of the truck wheel-base, and the results seem to satisfy all expec- tations. The usual two-wheel truck, Fig. 11 (b), is provided with a centre casting similar to that of the four-wheel, and hung in a similar manner on swing-links. It is controlled in its lateral movement by a radiusbar as long as can convenientlybe arranged. Theradial truck shown in Fig. 11 (d) is one introducedby the Brooks Worksabout 3 years ago. In itsessential parts itis similar to Mr. F. W. Webb’s truck on the London and NorthWestern Railway. Steelcastings are used as guides, and themain casting holding the bearings is also of cast steel. The movement is controlled by springs in a box underneath the axle. Until lately the use of the two-wheel truck was confined almost entirelyto goods engines, and tothe intermediate class known as ‘‘ Moguls,’’ and wasnot considered advisablefor fast passenger-engines ; but in the last 3 years some of the heaviest express engines built have been provided with a two-wheel truck at the leading end; the Baldwin Works has also a radial truck for the trailing end. Ro&.-The rods, both side and connecting, are of wrought iron or wrought steel. In some engines cast-steel side rods are success- fully employed. They are of I section, except sometimes in goods engines with a long coupled wheel-base, when a deep and thin rectangular section is not so rigid on curves, Fig. 12 (d). In the rods of I section, the web is f inch to 2 inch thick, while the thickness of the flange varies between $ inch in passenger engines, and as much as 12 inch in goods engines. The depth of the sections for main or connecting rods tapers from 5 inches at the small end to 7 inches or less at the big end. The width of the flanges of main rods is between 34 inches and 4 inches. Side rods of I section are of the same depth throughout their length. The web may be p inch thick, theflange g inch thick, witha section 22 inches wide and 5 inches deep. The Brooks and other works recommend for large goods engines the plain rectangular section for side rods. For these a usual section may be taken as S& inches by12 inch near the ends of the rod, changing to 63 inches by 1;- inch at thecentre.

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. ~rOOCedil~gS.] COWAN ON AMERIOAN LOCOMOTIVE PRAUTICE. 55 Main rods are now made as long as possible, within limits. For instance, rods in use on the Lake 8hore and Michigan Southern Railway, Fig. 12 (b), have 11-foot 6-inch centres. The main rods are provided with adjustment for taking upwear at both ends. At the small end, which is now invariably solid, a wedge and screw are employed for this purpose. At the big end, which is of the strap or jaw form, either cotters or a wedge and screw are adopted. No such arrangement is provided, as a rule, in the side rods, with the exception of the main crank-pin brasses, which are sometimes provided with a wedge and screw on each side of the brass, as shown in Figs. :L2 (B and d). A design of main-rod big end, worthy of notice, is shown in Fig. 12 (f), wherein it will be seen that the strain on the big end bolts is relieved by the block interlocking with lugs on the jaws of the rod. A modification of this 6orm has been in use for years on the Prussian State Railways; but in thisspecial pattern it would seem tobe applicable only toengines with outsidecylinders, where the crank is not so enclosed 8s it is with inside cylinders. The oil cellar below the brass is also another feature unknown to English practice ; it does not replace but supplements lubrication from a cup on the top in the ordinaryway. Crank-pins are made with liberal surfaces. Side-rod crank-pins 84 inches by 8& inches have appeared lately, while main-rod pins are often S&inches by S& inches, and even 7 inches by 8 inches. The crank-pin caps, for the driving and trailing wheels, screw on in the ordinary way; while those for the pins in wheels ahead of the main drivers are heldby a bolt which passes through the pin to the back of the wheel, where it is provided with a washer and nut. The crank-pins are forced into the wheels in the usual manner, and riveted over. Spring-gear OT Rigging.-The springs of an American enb’vine are always equalized or compensated. Thearrangement necessarily differs according to the wheel-plan. In engines with a four-wheel truck the coupled wheels or drivers and the truck are equalized independently. In “Atlantic”engines (4-4-2 type l) thetwo trailing wheels and the fourcoupled drivers areequalized together, while the four-wheel leading truck is independent. When two- wheeltrucks are employed, thetruck and the leading pair of drivers, or twoleading pairs, are equalizedtogether, andthe remaining drivers in a separate group. A single long lever with a fulcrumunder the cylinder-casting, as in Figs. 13 (c and d),

See p. 62.

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 56 COWANAMERICANON LOCOMOTIVE PRACTICE. [Minutes Of Plate 4, connects the spring-gearof the truck througha link and a cross piece with the springs for the driving-wheels (see transverse view inFig. 13, c). Springsare sometimes carried over the frames, and sometimes under them, or even between the front bars. In some engines the springs are directly over or under the axle- boxes, while in others they are situated between the axles (b). The plansadopted differ so widely that it is not possible to include themall under any general statement. The Brooks Workshas adopted theplan shown in Fig. 13 (b) for heavy engines, and states that the steady running of large locomotives is materially enhanced by placing the leading driving-spring across the frame, from box to box (Fig. 13, 71). The form shown in Fig. 13 (a), in use on the Lake Shore and Michigan Southern Railway, is a fair example of the use to which cast-steel may be put in such work, the brackets andbeams being of that material. BoiEers.-Considerable attention is given at the present time to the design of boilers. It is generally considered advisable to keep the engine parts proper as light as possible, and to put all the weight into the boiler, in order to obtain an engine of the highest possible steaming-capacity. English boilers are small compared with those on American locomotives ; and American designers now takefull advantage of theirlarger gauge-limits, whichrender engines of such large size possible. The height of the load-gauge on American linesvaries from about 14 feet on some roads to 16 feet on others; while in width 10 feet 5 inches is by no means uncommon for theover-all measurement of a cab. With these limits,very large boilers are possible, asthey may be centred highenough to cleardriving-wheels of anyusual size. The height of the boiler-centre is now raised as much as possible above the rail-level, and centres placed as high as 9 feet 8 inches or even 9 feet 10 inches above the rail-level are not unusual. The design of the boiler depends on the fuel obtainable. A deep fire-box is used with soft or bituminous coal, while for anthracite or mine slack a wide and shallow box gives better results. The narrow box alwaysrests on thetop of thebar frames, and is limited in width to a maximum of about 4 feet 13 inch, by the distance between the wheel-flanges, or rather thebacks of the tires. Thus only a small grate-area can be obtained, unless the box is very long. Forinstance, a fire-box D feet 4 inches in length millgive a grate-area of only 30 squarefeet ; and if it is lengthened to 11 feet, a grate-area of only 36 square feet is the result. Not only does a long box make the work of the fireman a great deal harder, but fuelis wasted, as the fireman:cannot arrange

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] COWAN ON AMERIUABLOCOMOTIVE PRACTICE. 57 it to the best advantage. In order to surmount these troubles, and to provide thelarge modernboiler withample grate-area for burning bituminouscoal, a compromise has been made between the regular narrowfire-box, and the well-known wide or Wootten box ; and one of moderate width and 1e:ogth is the result. The box is shortened to a slight degree, beingbrought back tothe more reasonable length of 9 feet ; and it is made perhaps G feet 8 inches wide. In this manner a grate-area of 50 square feet or more is obtained without difficulty, andthe resulting fire-box is much better suited to the huge heating-surfaccs provided in the boiler. This new design is received with great favour, and is being taken upas a long-sought impr0vemen.t. Alreadyfairly conclusive resultshave been obtained, showingits superiority, both in steaming and in economy of fuel, over the extremely long and narrow boxes. For burning anthracite, fine anthracite, or culm or mine slack, very wide fire-boxes are used, as shown in Figs. 14 (d and 7c), Plate 5, spreading rightover the frames, and measuring even 9 feet 7 inches in extreme width. A box of this width, and of a fair length, will give a grate-area of between' 70 and 90 square feet. Examples of modern boilers are shown in Figs. 14, all of which are typical of their several kinds; c, fi g, h, and k are for some of the heaviest engines built,namely, those illustrated in Plate6, Figs. 18, d, g, c, l, and a respectively. In Figs. 14 (a, b, c, and h) the back head of the fire-box slopes forward to some extent. This plan has many advantages. In most engines no brick arch is used, so that from the grate the flames are drawn direct into the tubes; and when the draught is strong they leave the back top corner of the fire-box almost untouched. The sloping of the back end brings the sheets, and therefore the water, nearer to the fire, and closer to the natural path of the flames in a box withoutan arch. It also enablesthe steam to leave theback-plate more quick1,y; and,instead of risingin contact with the plate all the way until it reaches the top of the box, the steam escapes from it at once, and is immediatelyreplaced by water. The back water-space is usually enlarged from 3$ inches or 4 inches at the bottom to sometimes even 9 inches at the topof tbe box. The Belpaire form of fire-box is extensively used ; Fig. 14 (f) shows one of the Player improved1 Belpaire boxes by the Brooks Works. Greatstress is laid on thefact that in this fire-box the crown of the box and the wrapper-sheot are stayed together andare in equilibrium. In order to preserve thisequilibrium,

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 58 COWAN ON AMERICAN LOCOMOTIVE PRACTICE. [Minutes of the stays from the hackhead are carried on pastthe wrapper- plate to the next sheet or course, and are so connected to one of the barrel-sheets. Fig. 14 (g) shows abox designed bythe Rogers Locomotive Works, where the sides of the outer shell are brought in considerably, so as to make the side staysalmost radial even at the top of the box. Here, however, the stays from the back head are connected with the wrapper-plate over the fire-box. The Pennsylvania Railroad has a somewhat similar form of box. Fig. 14 (c), a combination of the Belpaire box with a moderately wide grate, is another design by the Brooks Works. Some time ago the Pennsylvania Railroad applied the Belpaire principle to the wideWootten fire-box, but, it is understood, without any marked success. The boiler-barrels are usually not of uniform diameter throughout, and as a rule have one tapered ring or course, the position of which varies. The general shape, such as that shown in Fig. 14 (f),is known as a wagon-top barrel, that in Fig. 14 (U) is styled an extension or extendedwagon-top boiler. Barrelshaving an internal diameter of over G feet 8 inches at the largest ring are not uncommon; while the Illinois Central Railroad boiler in Fig. 14 v) has an internal diameter at the throat sheetof 7 feet 55 inches. Tube-lengthshave increasedenormously duringthe last 2 years. In 1900, B 16-foot tube was considered long;but many engines are now in service with tubes 22 inches in diameter, and 19feet long, or even 19feet G inches.’ Thediameter is either 2 inches or 2$ inches ; few engines are provided with tubes less than 2 inches in diameter. Ratios of length to outside diameter for the tubes of several modern engines are given in the Appen- dix (Table 11.).

1 The limit of 19 feet 6 inches has since been exceeded on engines of the 4-6-2 clas’s on the Chicago and Alton Railroad. These engines are remarkable for many features anda few particulars of them are here given:- Grate-area ...... 84 square feet.

Heating-surface,tubes ...... 3,848 9, 99 ,, ,, fire-bor ..... 202 ,I 1, ,, ,, total ...... 4,078 9, 79 Fire-box ...... 6 feet 04 inch X 9 feet. Tubes ...... Diameter 2$ inches. iLength 20 feet. Cylinders ...... 22 inches X 28 inches. Driving wheels(diamcter) .....6 feet 8 inches. Drivingwheel base ...... 32 feet 8 inches. Length of smoke-box (inside) .... 8 9, 5 $2 Total weight of engine ...... 97 tons 15 cwt. I qr. P. J. C., July, 1903.

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Prpceedings.1 COWAN ON ANERICAN LOCOMOTIVE PRACTICE. 59 Thethickness of plate rendered necessary by large boilers and pressures of 200 lbs. to 225 lbs. persquare inch is much greaterthan is customary in :English engines. Barrel-plates are frequently 3 inch thick, and in the large engines they attaina thickness of 1 inch. The wrapper-plates, or fire-box shell-plates, are & inch to T% inch thick; while the throat-sheetis 9 inch or 1 inch, and the back head is 4 inch or 4 inch in thickness. The crown and sides of the box are 3 inch or & inch thick, while thefire-box tube-plate is 4 inch or -i;- inch, and the fronttube-sheet is Q inch or 2 inch thick. Analyses as well as mechanical tests are demanded for boiler and Ere-box steel. Limits of between 24.6 tons and 29 tons per square inch are fixed for the tensile strength, with an elongation of not less than 20 per cent. in 8 inches. An example of the analysis demanded is-

Boiler Steel. Fire-box Steel. ~ Per Cent. Per Cent. Carbon between . . . . 0-15 &0.25 0.15 & 0.25 Phosphorus not exceeding . 0.05 0.03 Manganese ,, ,, . . 0.45 0.45 Silicon ,, ,, . . 0.03 0.03 Sulphur ,, ,, . . 0.05 0.085 Stay-boltsare always of wrought iron, whichmust have an ultimate tensile strength of 21 -4 tons per square inch, and give an elongation of 25 per cent. in 8 inches ; the cold metal must also pass the double-bendingtest. The subject of flexible stay-bolts has been carefully gone into,and some lineshave hadthem in use for many years. Thenarrow water-spaces in many of thelarge modern bloilers withnarrow fire-boxes cause great.trouble from broken stay-bolts. Some of themany forms of staysworking in ball-joint sockets are reported to obviate this trouble satisfactorily. The difficulty is also largely reduced by the use of the widerboxes with larger water-spaces. Tubes are of charcoal iron or of drawn steel. They are tested to a hydraulic pressure of 500 lbs. per square inch, and will stand without injury far more than that ;amount. Short lengths 13 inch long arestood on end under a hammer, and must stand hammering flat into a ring without developing any transverse cracks-a test which, though severe, is passed without difficulty. The heating-surfaceprovided is large, even compared with large English locomotives. For passenger engines, 2,000 squaqe feet to 3,000 square feet is commonly provided, and 3,000 square feet to 5,300 squarefeet in heavy goods engines, of whichabout 200 square feet is in thefire-box.

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 60 COWAN ON AMERICAN LOCOMOTIVEPRACTICE. [Minutes Of The smoke-box is continuous with the boiIer-barrel, and is fitted with deflectors and spark-arresters, as shown in Figs. 15, Plate 5. The low blast-pipe combined with a petticoat-pipe is believed to be of still more recent introduction in American practice than in English. Boilers are caulked insideand out. Pneumatic tools arenot used for this purpose so largelyas might be expected. Holes arepunched or drilled before thesheets are put together, and do not by any means always '' come in '' : so that the holes must berimered out and larger rivets be inserted. Thegroup of holes withwhich most trouble is experienced is thatwhere the wrapper-plate, thethroat sheet, andthe nearest plate in the boiler-barrel, come together. The tube-holes in the tube-sheets are punched, and the plate is straightened afterwards ; it is usual to punch them 4 inch to

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] COWAN ON AiUERICAN LOCOYOTIVE PRACTICE. 61 admittedthat this is a good feature. It saveslabour, and on a windy day italso saves the engine from becoming covered with ashes. Theash-pan is frequently,though not always,provided with bottom or drop doors ; and the sides are sloped stuep enough to make them self-emptying, so that no hose is needed to clean them out. Smoke-boxes, as a rule,are also provided with some form of dumping arrangement. Boiler-mountings are provided withnarrow faces andheavy flanges. Ball-joints, struck to a radius of between 3 inches and 7 inches, are often used, instead of English wide flat-faced joints ; the joints so formed are very satisfactory, and last as long as any other parts of the engine. Regulators are of the balanced kind, and the pipe-joints are all. ball- or cone-joints ground up. Steam-pipes in the smoke-box are of cast iron, and arealso provided with ball-joints. The smoke-box door is not fastened by a single centre bolt and cross bar, but is tightened up bysometimes as many as eight or ten clips spaced at intervals round its edge. Thisobviates to some extent the careful work needed in the English form in order to obtain a thoroughly air-tight joint. Use of CastSteel.-Cast steel is extensively used now in loco- motivework, butnot equally so by all builders. Whilethe Baldwin Locomotive Works, for instance, still uses a large amount of simple wroughbiron work, the Brooks Works often substitutes cast steel in the same parts. Frames are frequently made of cast steel, though the ordinary rectangular-bardesign seems but poorly adaptedto steel-casting. Noresuitable designs arebeing introduced, however, as for instance some I-sectionframes on the Delawareand Hudson Railroad. Frame-filling pieces are often of cast steel; as are numerous other parts, many of which have hitherto been of cast iron. The present design of steel castings is different from what was considered necessary when this material was first extensively employed. Originally the plain patterns and designs for cast iron were used, thus giving an equally heavy casting, but one possibly a great deal stronger than if cast iron had been employed. " Possibly " is said advisedly ; for these designs were often so ill-adapted to steel casting that very porous and weak castings were the result. At the present day, however, great care is exercised, when employing cast steel, to take full advantage of the possible saving of weight. Greater strength is not always needed ; and often equal strength with less weight is of considerable advantage. The casting is now generally of the web-and-flange kind, and the web is cut aiay if the strength of

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 62 COWAN ON AiUERICAN LOCOYOTIVE PRACTICE. [Minutes of the casting will allow of it. Large masses of metal are studiously avoided. The qualityof the castings is not always above reproach ; though, if great reliabilityis desired, doubtful castings are always put on one side. Not only is cast steel used for frames and frame- castings, yokes, slide-bars, pistons, wheel-centres, etc.,but it isalso employed for the equalizing beams of the spring-gear, for large portions of the motion such as valve-rods and reversing-shafts and alsofor side rods. The tests specified forcast steel vary. Many railwaysinsist on one qualitybeing employedfor all castings, including wheel-centres,for whioh thetests already mentioned will then apply to the rest of the oastings.

MODERNAMERICAN LOCOXOTIVES. The names applied to the various classes of engines are multi- tudinous and wonderful, and frequently lead only to confusion. Among instances of this kind may be cited such classes as those generally called the Atlantic,” the Chautauqua,”and the “North West.” The first is by the Baldwin Works, and is illustratedin Fig. 17 (a), Plate 6. The second isby the Brooks Works, andis illustrated by Fig. 17 (c). The chief difference betweenthese two engines is that the trailing wheels of the second are fitted with a radialtruck, while in the “Atlantic” class they form part of the rigid wheel-base. The third class is illustrated in Fig. 17 (b), and is built by the Schenectady Works; but it is hard todiscover what other claimit has toa separatename. In this Paper a. simple system of olassification, already used to someextent in America,will be adopted, wherebyengines areclassed according to their wheel-plan.Thus, the “American,”or eight- wheel passenger engine, will be termed a, (‘4-4,” because it has a four-wheel truck, followed by four coupled drivers. Carrying out this system the following classes are obtained :-the LLAmerican” or four-coupled bogie passenger engineis aL‘ 4-4 ” ; the U Atlantic,”

‘6 Chautauqua,” ‘L North West,” and ‘‘ Central Atlantic,” which are all alike as regardswheel-plan, become “ P4-2 ” ; the Mogul ” will be known:as ‘‘ 2-6 ” ; ten-wheel passenger engines are 4-6 ” ; the “ Prairie ” class is “ 2-6-2 ” ;the class illustrated in Fig. 17 (ii), for which as yet no name appears to have been found, becomes

6‘ 4-6-3.” L‘ Consolidations ” are of the 2-8 ” class ; L‘Decapods,’’ orten-coupled engines, are of the 2-10 ” class ; Mastodons,” or twelve-wheel goods engines, are of the ‘L 4-8” class;and Switchers ” or shunting-engines are the‘‘ 6 ” class. Passenger Lccomotives.-Until recentlypassenger trains have

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Pro~eding8.1 COWAN ON AXERICAN LOUOMOTIVE PRACTICE. 63 been mostlyworked by 4-4 engines, whilethe local trains,or stopping trains on the main lines, were worked by the 2-6 class. Tbe latter engines, although much heavier than they were a few years ago, are now among the lighter enginesused for such service. A heavy P4 eugine weighs about G23 tons, of which 35 tons to 40 tons rests on the driving-wheels. The fast and heavy traffic of modern days, however, oalls for much greater power than it is possible to obtain in an engine of thiskind, and has led to the several developmentsshown in Figs. 17, Plate 6. Traffic now demandsa powerful engine, not only capable of making a run at a high speed, but also able to maintain amaximum speed fora run of 50 miles or more, if necessary, and still to have a margin of power for rising gradients or for making up lost time. Considerable stress is laid on keeping time between termini and important stations, and for this purpose high speeds are required. Such conditions naturally call for an engine with amplesteaming-power, as well as ability torun at a high speed ; it would be of little use without plenty of steam to feed it. The first successful class designed for this work is the 4-4-2, shown in Plate 6, Figs. 17 (a,b and c). Here the large driving- wheels are placed in front of the fire-box. The boiler is not then limited in thesame way as ina 4-4 engine, and a wide or narrow fire-box may be chosen, according to the fuel available. Engines of this kind used to be about 67 tons in weight, with a heating- surface of not more than 3,000 square feet, and a grate-area, according to the fuel used, of 86 square feet, 40 square feet, or 28 square feet. The heaviest engineof this class, recently built by the Baldwin Works, weighsas much as81 tons 14 cwt. of which more than 44 tons is supported by the driving-axles : it is on the Chicago, Burling- tonand Quincy Railroad. Theengine shown in Fig. 17 (a) is one of those doing the famous run from Camden to Atlantic City, a timed trip of 55.$ miles regularly worked in 50 minutes. The Chicago and North Western Railway engine shown in Fig. 17 (a) was the first of this class built by the Schenectady Works; and almost immediately afterwards the same works turned out some similar, though heavier, engines for the New York Central and HudsonRiver Railroad. Thelatter engines weigh 78.$ tons and are provided with a simple form of traction-increaser, whereby the weighton the driving-wheelsmay be increased at startingfrom 42 tons to 48 tons. The fire-boxes are moderately wide and the boiler has over 3,500 square feet of heating-surface.

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 64 OOWANAMERICANON LOCOMOTIVE PRACTICE. [Minutes Of TheBurlington, Cedar Rapidsand Northern engine, Fig. 17 (c), is one of a now popular kind, fitted at the trailing end with the Player radial truck illustrated in Fig. 2 (d), Plate 4, thus reducing the long rigid wheel-base of this class. Engines more recently built are heavier, and are provided with more heating- surface; but this particular example is of interest, owing to the factthat it was one of the firstengines fitted with the radial trailingtruck, and also on account of its boiler, illustratedin Fig. 14 (c), Plate 5, in which large grate-area is combined with the Belpaire form of fire-box. The next important class dealing with still heavier traffic, but perhaps not quite so fast, is the 4-6 engine depicted in Figs. 17 (d, e and f), Plate 6. Although a six-coupled engine, and consequently perhaps atsome disadvantage in express service,this would seem to be the most rational modification of the 4-4-2 class where increased power is required; for here the weight of the trailing wheels is utilized for adhesion, whereas in the4-1-2 class increased weight of engine produces no corresponding advantage in adhesion. The 4-6 engines have now been in successful use for some years. Naturally, they are notused for light traffic on the level divisions, butare employed on theheavier trains, consisting of nineto twelve cars, and on the more difficult sections of the lines. With 4-6 engines designed for burningbituminous coal, i.e., having a narrow grate, as large driving-wheels may be obtained as with the4-4 engine. For passenger service, however, anthracite coal is used wherever possible, owing to its freedom from smoke and grit. Thiscoal requires a large grate-area; andto obtain a large trailing wheel with a wide grate is a matter of some difficulty. It would therefore seem that in this direction the 4-4-2 engine has an advantage over the 4-6 engine. In A.merican practice,a wheel 6 feet 8 inches on the tread is considered very large, and but few engines are provided with drivers of larger diameter. It is true that locomotives of the 4-4-2 class have frequently 7-foot or 'I-foot l-inchwheels; but with this class ratherlarger wheels are possible than with the 4-6, in which the drivers are seldom more than 6 feet 8 inches in diameter, or G feet for engines with wide fire-boxes. In a 4-4-2 engineon the Philadelphia and Reading Xailroad having 'I-fOOt driving-wheels, wheel-pockets have had to be formed in the boiler-barrel in order to allow for the flange of the tire ; but the gauge of the line is somewhat less in height than thatof most American roads, so that in this engine the boiler-centre has to be kept comparatively low. The next and latest derelopment in use in passenger service is

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] COWAN ON AMERICAN LOCOMOTIVE PRACTICE. 65 the 2-6-2 class, shown in Figs.17 (g and h). . Heredriving- wheels of largediameter are combined with awide fire-box in a six-coupled engine. The combination is obtained by groupingthe driving-wheels in front of the fire-box, as is done in the 4-4-2 class; but owing to the fact that there are three driving-axles, the leading pair of driving-wheels has to be placed so far forward that a two-wheel truck takes the place of the four-wheel truck in the former] classes. The trailing end is supported bya two-wheel truck, SO that the rigidwheel-base is confined to that of the driving-wheels. The first notable engine of this class wasthat shown in Fig. 17 (g), built for theLake Shore and Michigan Southern Railway by the Brooks Works in the winter of 1900-1901. Like all the engines of that line, it is conspicuous asan example of a thoroughand careful design, in which lightness of moving parts has been specially considered. It is open to the objection that the yoke is fixed to the boiler- barreldirect, as already mentioned; but it will be seen that with such a wheel-plan this is a difficult matter to arrange. In more recent engines-those built, forinstance, by the Baldwin Works for the Atchison, Topeka and Santa Fe Railroad, Fig. 17 @)-the difficulty has beensurmounted, and the yoke is fixed, as it should be, tothe frames. Fig. 17 (h) represents indeed the heaviest class of passenger locomotive extant; it is a very powerfulengine, havingat the same timedriving-wheels not exceeding 6 feet 7 inches in diameter, which it is now certain are large enough for anywork. For comparison between a heavy 4-4 engine and this Atchison, Topeka and Santa Fe locomotive a few particulars of each are here given :-

N.Y.C. S H.R.R.R. I A.T. & Pa.F.R.R. 4-1 Engiue. -2-6-2 Engiue. Cylinders ...... 19 X 24 inches 17&28~28inches Weight on driving-wheels ..... 12 tons 3 cwt. 64 tons 2 cwt. ,, of engine ...... 65 tons 7 cwt. 94 tons 2 cwt. Diameter of driving-wheels .... 6 feet 7 inches 6 feet 7 inches Heating-surface, tubes ...... 2,224 sq. feet. 3,543 sq. feet. t ,, fire-box ..... 180 I, 9, -195 I, ,, 1, ,, Total ...... 2,404 ,, 3,738 $9 $3

Grate-area ...... 30.7 9, $9 53'5 ,, 5,

[THEVOL. INST. C.E. CLIV.] F

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 66 COWAN ON AMERICANLOCOMOTIVE PRACTIUE. [Minutes of In the 4-6-2 class, illustratedby the recent Chesapeake and Ohio engine in Fig. 17 (k), Plate 6, a four-wheel truck takes the place of the two-wheel leading truck of the preceding class. This involvesa still greater increase of wheel-base, up to 32 feet 8 inches; but, all things considered, a four-wheel leading truck is preferable to a two-wheelfor passenger-work. The total wheel- base of a 4-4 engine may not bemore than 23 feet 6 inches, while that of the last two classes is nearly 9 feet more ; the wheel- base of the engine in Fig. 17 (h) is 32 feet 2 inches. The engine illustrated in Fig. 17 (k) is also notable as having tubes 19 feet 6 inches long ; they are the longest tubes ever used in a locomotive,l and their diameteris 2a inches. The true intermediateclass between passengerand goods engines is the 2-6 engine, ordinarily known as the " Mogul " class. These also have increased in size and capacity of late ; but the general design is muchthe same as it used to be, and no engines of this class worthy of particular notice have been built. In the pastthey formed a useful class for handlingwhat was then the heavier andslower passenger traffic and the fastergoods traffic ; but on most lines more powerful engines arenow required for this work, and such traffic is now handled by engines of the 4-6 class. Reduction in the numberof classes of engines on a line is sometimes effected, with the result that an intermediate class is built. The 4-6 engineis taken, perhaps originally designedfor passenger service, and is fitted with smaller driving-wheels;the truck centre is correspondingly altered, and the engine is fitted for fast goods service. Thusthe Pennsylvania Railroad, inits G4 and G4u classes, has an engine with 6-foot driving-wheels for passenger service, andan engine exactly similar in allother respects, but with wheels 5 feet 2 inches in diameter, for goods traffic. The Union Pacific has also several classes of ten-wheeledengines, but they differ in other respects besides the wheels; here again one class has driving-wheels 6 feet in diameter and another has wheels 4 feet 9 inches in diameter. On lines where gradients are long and severe, six-coupled passenger engines areof great service with trainsof the heavyAmerican cars ; and it must be remembered that, particularly in the west and even in some parts of the east, very hilly countryis encountered. The speed of the best passenger trains in the western States rarely exceeds 35 miles per hour : SO that on this work no exception can be taken to the use of six- coupled engines,which, however, are now in general use for

See foot-note, p. 58.

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Prooeedings.] COWAN ON AMERICAN LOQOMOTIVEPRACTICE. 67 many of the fast trains in the eastern States, where the speeds attained are considerably higher. Goods Locomotives.-Goods are handled by 2-8,4-8, and 2-10 engines;and all these classescomprise machines of enormous weight and capacity. The “Consolidation,”or 2-8 engine, isthe natural outcome, years ago, of the demandfor an engineheavier thanthe 2-G. In heavyengines of this kind about 10tons weight is on the truck, and the remainder is availablefor adhesion. In the heaviest of them it has been necessary to put a weight of 11 tons 4 cwt. on the truck, as in the Pittsburg, Bessemer and Lake Erie engine, Fig. 18 (d). Very heavy enginesof this kind are said not to ride at all well on the road; and some builders recommend the 4-8 class as preferable in this andother respects. So far as adhesive weight is concerned, the advantageis on theside of the 2-8 engines, whichsupport only about 11 tons on theleading truck, and the remainder on the coupledwheels; while in the 4-8 engine as much as 18 tons is sometimes on the four-wheel truck. A class which has grown in importance in recent years is the 2-10, which now includes the heaviest engines in existence : such for instance, as those illustratedin Figs. 18(I and m), Plate 6. Theso last engines, Fig. 18(m), built for the Atchison, Topeka and Santa Fe Railroad by the Baldwin Works, have a total heating-surface of 5,390 square feet. The cylinders are 19 inches and 32 inches in diameter and 32 inches stroke, while the engine weighs 119 tons 11 cwt.-a limit it would seem almost impossible to exceed, even with the large width and heightof gauge in use on that line. In England engines of such large size have been criticized as altogether uneconomical and unnecessary. It must be borne in mind,however, that American goods traffic is handled quite differently from English. Goods-trains on level sections are sometimes made up of no less than one hundred cars, all of which are long bogie-cars ; for the small four-wheel wagon is practically unknown in America, except in the form of dumping-cars Tor contractors’ purposes. Frequently there areover ninety cars in a train. On a hilly section the load is reduced. The Union Railroad in the Pittsburg districtowns oneof the heaviest 2-8 engines in existence, but it has only the one engine of this size. The Pittsburg,Bessemer andLake Erie owns twoengines, Fig.18 (d], evenheavier thanthat on theUnion Railroad; but they are employed in hauling practically none but heavy trains of iron and iron ore between theLake port and the steelworks of thePittsburg district connected by this line. A full train-load for these engines F2

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 68 COWANAMERICANON LOCOMOTIVE PRACTIOE. [Minutes of is considered to be nearly 2,500 tons. Withthe steel cars in we, this leaves a paying load of nearly 1,746 tons. The engines areas a rulewell loaded, because the traffic isfairly regular. The run is 150 miles long ; and gradients rendera helper necessary for about 46 miles of this distance. The Lehigh Valley Railroad engines, illustrated in Fig. 18 (a), Plate 6, take a train of 890 tonsup the Wilkes-Barre moun- tain “ cut off” against a gradient of 1 in 88. The length of the

$6 cut off” is only 22 miles ; and the Author understands that the work of these engines is confined to this section of the road. The practice on the Great Northern Railway (America) is to run goods trains at a speed of 10 miles per hour, and cattle trains at 20 miles per hour. An engine with cylinders 19 inches by 32 inches and 200 lbs. per square inch boiler-pressure is scheduled tohaul 890 to 1,520 tonsbehind the tender on the Cascade division of this road ; while on the Northern division with easier gradients the trains exceed 1,780 tons with much less powerful engines. The Illinois Centralengines, Figs. 18 (c and g), are rated to haul 1,780 tons behind the tender, upa gradient of 1 in 150, at a speed of 20 to 30 miles per hour. This is just double the rating for some of the older classes ; and these large engines have been run with atrain-load behindthem of 3,125 tonsup a gradient of 1 in 220. They were the subject of a report published by the Illinois Central Railroad not long ago, in which they did not show up as well as might have been expected, owing mainly to the fact that there was great difficulty in loading them to their full capacity. The difficulty of always loading a big engine fully isconsiderable, unless the line be such as the Pittsburg,Bessemer and Lake Erie, which has a steady traffic of ore, or unless the engine is used for hauling traffic over some particularly difficult section of the road, such as the “ cut off” on the Lehigh ValleyRailroad, already referred to. The Southern Pacific engine, Fig. 18 (b), working a section of the line which rises nearly7,000 feet in about 83 miles, including 50 miles up a gradient of more than 1 in 50, draws a train of about 445 tons behind the tender. The 2-10 engine on the Minneapolis, St. Paul and Sault Ste. Marie Railroad, used between Minneapolis and Pennington (Wis.), a distance of 165 miles, runs over a line having the ruling gradient of 1 in 126, while the most severe gradient on the section is 1 in 81, lasting for 7 miles. On all but this short section the engine

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] UOWAN ON AMEBICANLOCOMOTIVE PBAUTICE. 69 in Fig. 18 (k) is guaranteed to take a load of 1,780 tons at a rate of 6 miles perhour; the load is sometimes exceeded by more than 180 tons. The powerful engines in Figs. 18 (1 and m) are intended fcr regular road service on the Atohison, Topeka and Santa Fe Rail- road, and it is said the line will shortly have over seventy of them. Coal-consumption is too large a question to enter into here; but lines which keep their statisticson a ton-mile basis, and on which the heavy engines are more or less regularly loaded, report that the use of such engines is distinctly economical. Should it always be possible to load them fully, it is evident that working-expenses must be less, owing to the reductionof train crews, if for no other reason. Compared with one of the heaviest of British engines, the consumption per mile would appear to be enormous ; but if it is worked out on the ton-mile basis, in which the load hauled is takeninto account, it becomes at once more reasonable. These large American locomotives frequently consume over 150 lbs. of coal per mile; but if theload is taken into account, even this consumption may prove to be well within the limitof economy, when compared with that of lighter engines. Fig. 18 (n), Plate 6, shows a simple example of a switching- or shunting-engine. Such engines, requiring, as they do, atender, naturally take up a great deal more room in the yard and sidings than do English tank-engines. Someof themare very heavy : the one illustrated weighs nearly 65 English tons for the engine alone. Shunting is frequently performed by hauling or by poling. In the former method hawsers are used, and the engine on one line hauls the cars along on another line alongside. In the second plan a strong pole is used, and the engine-buffer and the car-sill are both provided with cups to take the ends of the pole; here again the engine runs on one road, while the carsto be pushed by the pole are on a parallel road. Generally, it may be said that there are features in most of the contract-built engines, whereby it is often easily possible to recog- nize the builders. Compared with the extremely neatly-finished British locomotives, the American engines are not elegant machines. Considering them as a distinct class, however, decidedly good-look- ing engines maybe found among them. The Baldwin Worksseems to pay but little heed to this point, and does not seek for graceful lines in any respect. Almost everything gives way to cheapness of production;everything possible is made square, orrather

rectangular ; curves seem to be avoided ; and the work is of the simplestpossible form anddescription. No troubleis taken in obtainingparallel lines,or in harmonizingcurves; and froma purely asthetic point of view the general Baldwin locomotive is very crude. The Pittsburg Works seems to proceed on much the samelines. In the eastern States, however, the Brooks and the Schenectady Works turn outmuch neaterlocomotives. At the latter works great care is taken, more especially over export orders, to build engineswith the leading characteristics in keeping those with of the ordering line. This was especially noticeable in the order placed by the Midland Railway of England for engines in 1899, part of which went to the Baldwin, and the rest to theSchenectady Works. The Baldwin engines were typically inelegant; while the Schenectadyengines, though doubtless of slightly higher price, were all that could be desired in outward appearance, and con- formed closely to most of the leading features of the home-built Midland engine;the tender, it is understood, was of standard Midland pattern, or nearly so. In enginesfor home use, the SchenectadyWorks does notlead in this matter; the foremost position isunquestionably held bythe Brooks Works,whence engines of very neat appearance are continually being turned out. It is difficult to make an American locomotive really graceful, and it is doubtful whether it is ever attempted; but the exterior of the averageBrooks engine iscertainly neat, and the lines harmonizebetter, and the curvesare more graceful, thanin engines builtby any other firm inthe States. Thiscriticism does not apply to exterior appearance only ; the same principles are carriedthroughout the Brooksengine. Castings are carefully designed and of gracefulform, and pains are taken to lighten them wherever possible. Nowhere does the design appear to have been got out forcheapness; and while the latter point is kept prominently in view in the drawing-office,care is taken to do the work; thoroughly, and at the same time with some regard to appearance-a feature that seems to be entirely lacking in some works. The engines arenever painted to the degree of perfection which is reached in England. The boilers, lagged with magnesia-asbestos block lagging, arecovered with planished iron, which if kept oiled lasts almost indefinitely. The Schenectady Works provides a simple form of clip, whereby the sheets at the sides of the fire-box may easily be removed for the inspection and renewal of stays. The frame and interior work are painted black ; and the wheels are

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] COWAN ON AMERICANLOCOMOTIVE PRACTICE. 71 painted, lined, and varnished.The cab, whichis of wood or steel,is likewise painted, lined, and varnished; as are also the tender-tank and wheels. Little time is spent over such work as rubbing down and stopping; consequently the finishedwork, as a rule, is streaky. Lettering is done in coIour, or in gold or silver leaf, and is of a prominent character.

The Paper is accompanied by six sheetsof drawings, from which

, Plates 3-6 havebeen prepared; and by the followingAppendix, descriptive of these illustrations.

[APPENDIX.

APPENDIX.

NOTESON TEE ILLUSTRATIONS. THEillustrations of this Paper, with two exceptions, are from official prints supplied by the Superintendent of Motive Power of the line, or by the builders of the locomotive in question. Some of them are more or less diagrammatic : which is rendered unavoidable by the style of prints and drawings used in Inany of the American shops. In order to obtain a complete drawing of any large portion of an engine, sometimes a number of different prints have to be obtained, andthe parts pieced together. Plate 5 especially is of a diagrammatic character, here rendered advisable to some extent, in order to avoid confusion of lines, etc. In Plate 6 wheels are shown diagrammatically; only the tread of the tire and the periphery of the flange are drawn. Blank or flangeless tires have not been shown in every case where they are used ; but their use is not SO general as it was formerly, and, except on engines of very long coupled wheel-base, all tixes are now provided with flanges. In Plate 6 the figures relatingto the weights refer generally to weight in working order. Fig. 17 (h) is an exception: the weights of this engine in working order are those already given (p. 69, namely, 64 tons 2 cwt. on the driving-wheels, 13 tons 5 cwt. on the leading truck, and 16 tons 15 cwt. on the trailing truck; total 94 tons 2 cwt. for the engine in working order. The weight of the tender is not included or referred to in any instance.

INDEXTO ABBREVIATED NAME#OF AMEEICANRAILWAYS. A.T. & Sa.F...... Atchison, Topeka and Santa Fe Bailway. B. & 0...... Baltimore and Ohio Railroad. B.C.R. & N...... Burlington, Cedar Rapids and Northern. B.R. & P...... Buffalo, Rochester and Pittsburgh Railway. C.N.J...... Central Railroad of New Jersey. C. & 0...... Chesapeake and OhioRailway. C. & N.W...... Chicago and North-Western Railway. C.B. & Q...... Chicago, Burlington and Quincy Railroad. C.C.C. & St. L. (“Big Four ”) . Cleveland, Cincinnati, Chicago and St. Louis Railway. D.L. & W...... Delaware, Lackawanna and Western Railroad. G.N...... Great NortbernRailway (America). I.C...... Illinois Central Railroad. L.S. & M.S...... Lake Shore and Michigan Southern Railway. L.V...... Lehigh Valley Railroad. M.St.P.& S.Ste.11. ....Miuneapolis, St.Paul and Sault Sto. Marie Railway. N.Y.C. & H.R...... New York Central and Hudson River Railroad. N.Y.N.H. & H...... New York, New Haven and Hartford Railroad. N.P...... Northern Pacific. P...... Pennsylvania Railroad. P. & R...... Philadelphia and Reading Railway. P.B. & L.E...... Pittsburg, Bessemer and Lake Erie Railroad. S.P...... Southern Pacific Railroad. u...... Union Railroad. U.P...... Union Pacific Railroad.

TABLEI.-PABTICULABS OF ILLUSTBATIOHS.

Fig. Detail. Railroad. I Engine. I Builders.

Plate 3. la Cylinder . . . N.Y.C. & H.R. Fig. 17 f b ,, . . . P.B.&L.E. Fig. 18 d Pittsburg. C ,, . . c. & N.W. Fig. 17 b Schenectady. d ,, ....l 1.0. Fig. 18 g Brooks. e 10-wheel pass. ,, . . .S P. tngine, Q 4 class l f C.C.O. & St. L. 10-wheel pass. , . ‘{l Four.)(Big ‘ Vauclain comp. t Vauclain comp. 9 11 . . . i L.V. { Fig. 18 a i h ... S.P. Fig. 18 b Schenectady. 2a Steam-chest cover. b Bteam-cheat casting l} N.P. .. , c L.P. cylinder-cover N.P. Compound ,, 3a Piston,cast-iron . S.P. b L.P. piston, cast- .. steel . . . .1 S.P. C Piston, cast-steel . Y.B. & L.E. Fig. 18 d Pittsburg. d Piston . . . . C. & N.W. 4a Crowhead . . . I S.P. .. Schenectady. b Brooks. 29 .. *I .. .. c ... .. Baldwin. d . . . 1 B.&O. Vauclain comp. e ,, Laird . S.P. .. Schekctady. 10-wheel pars. I 5a Motion . l . . . p. G4 class J 7) ...... l .. .. Baldwin. 6a Eccentric eyp.,]l cast-iron . .. Schenectady. b ,, N.Y. N.H. &- H. c Eccentricstrap, malleable cast-” 1, U.P. iron . . . . a Eccentric . . . 1 U.P. Brooh. e 97 . . N.Y.C. & H.R. 7a Frame . . . . l C.&O. S-whoa1 pasa. 3chenectady. 6 ,, . . . . i C. of N.J. “Atlantic” Baldwin. “ North-West” 1 C ,, .... Schenectady. & N.W. { (Fig. 17 b) J d ,, B. C. R. &N. t Brooks. . . . . 1 { “~i~~&;;qD;&” IO-wheel pass. , e ,, .... P. {l engine * f U. ‘‘ Consolidation ” Pittsburg. 12-wheel goods 9 ,> .-. ’ Brooks. *I {l (Fig. 18 g], M.St.P. & , “Decapod h ” ‘ * * i( S.Ste.M. 1 (Fig. 18 k) . Baldwin. ‘‘ Decapod ” 1 k 1, ... 1 A.T. & Sa.F. 1 hheneclady. .l (Fig. 18 2) Sa %bar guide .. .. Baldwin. 1) %.bar ,, . .*l , .. a %bar ,, . . .. Bribks. d Cast-steel bars. ./ B.&O. Vauclain comp. Baldwin.

Cylinderto go withframe in Fig. 7 e. * Cylinders Fig. 1 C.

c. 6- N.W. ~ Plate 4. 11 a 4-wheel truck . . P. J I 10-wheel pass. b 2-wheel ,, . . 11 G4 class C 4-wheel ,, L.S. & M.S. d .. Brooks. 12n L.T. ‘‘ Atlantic ” 1 I3aldwin. rods . . . . l

b I9

C tl

& el , ,, ihL6t.P. S.Ste.M!( ‘‘:F&?::’ Baldwin f Large endof main- .. Ihooka. rods . . . .j .. 13Cl Spring rigging . ’ L.S. & M.S. j 10-wheel pass.Z 3 6 5, ,, ., D.L. 6- W. ,, ,, 1, C ,, ., , L.V. Coneolidation ” Baiiwin. d >I 3, AT. 6- Sa.F. “ Decapod ” Schenectady. Plate A. ( 10-wheel pass. 14a Boiler 1’. . . . . ~’( G 4 clas!, b ), .... A.T. & Sa.F. ‘‘ Prairie Baldwin. C ), .... B.C.R. 6- N. I ‘‘ Chautauqua ” Brooks. (l I, .... D.L. 6- W. 1 10-wheel pass. e ,, .... ]’.B. 6- L.E. ‘* Consolidation ” Pitiiburg. J ,,.... I.C. 1 12-wheel goods Brooks. n ,,.... I.C. ‘‘ Consolidation” ltogers. h ,,.... A.T. & Sa. F. , Decapod” Schenectady.

It‘ ), . . . , L.Y. ~ ‘‘ Consolidation” Ualdwin. 15n 1 Front end arrange- 8.P. ’ ‘‘ Consolidation ” Schenectady. ment. . . . , b 99 C.B. & Q. , “ Atlantic ” Baldwin. I.C. 12-wheel gyp Brooks. 16; 1 ExhLust-pipe tdp P. & 1:. “ Atlautic Ilaldwiu. b Corner of founds:) .. I3aldwiu. i tion ring . . , c ’ Wash-out pIug-hole‘; ..

Since these engines were built the number of tubes has been reduced from 511 to 502, andthe heating-surface in thetubes has been correspondingly diminished from 3,890’6 square feet to 3,824.7 square feet. Showing use of steel castings. Showing transverse spring over leading axle. ’ Pressed out in the sheet.

TABLEI.-PARTICULARS OF ILLlJSTRATION8-continued. , Class of Engine. l I Railroad.: , Builder. Description. Wheel-plan.1 - I I

Plate 6. i ’‘ Atlantic” 1 4-4-2 I 1’. & R. , Baldwin. b I North-West ” C. &- N.”. Schenectady. Brooks. c ‘‘ Chautauqua” ,, ~ I3.C.R. &N.

d ~ 10-wheel pass. ’ 4-6 D.L. & W. ,,

e L.S. &- 31,s. ,P f N.Y.C. & H.R. Schenectady.

“ Prairie ” 2-6 - 2 L.S. & MS. , Brooks. A.T. & Sa.F Baldwin. 4-6-2 c. & 0. Schenectady.

l “ Consolidation ” ! 2-S L.V. Baldwin.

S.P. I Schenectady. i ,, I.C. 1 Rogers. , P.B. & L.E. ~ Pittsburg. 12-wheel goods 1 4-5 D.L. & W. C.R. &P. 1 l I.C. l

r.r. 1.

‘’ Decapod ’’ 2-1 0 1I.St.P. &. S.Ste.nl. ~ Baldwin. i A.T. 9r Sa. F. Schenectady.

11L Baldwin.

11 Switcher G G.N. ~ Brooks.

See p. G2.

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